Modifier for phonographs.



No. 840,526. PATENTED JAN. 8. 1907.

A. s. THOMPSON.

REGDIFIER FOE PHONOGRAPHS APPLICATION FILED HAB..31.1906.

. UNITED ST TE PATENT OFFICE. p

ASHLEY s. THOMPSON: OF CHICAGO, ILLINOIS. M'QDIFIER FOR PHONOGRAPl-IS.

Specification of Letters Patent. I n iloiaonnta Inch 31,1 06. Seria1No.809,037.

Patented Jan. 8, 1907.

To all whom it may concern:

Be it known that 1, ASHLEY S. TnomrsoN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Modifiers for Phonographs, of which the following is a specification.

' view of a phonograph or graphophone with a portion of the horn broken away to show the modifier device in place therein. Fig. 2 is a top plan View of the modifier, and Fig. 3 is a sectionalview on the line 3 3 of Fig. 2.

Like reference-numerals indicate like parts in all of the figures.

10 is a diagrammatic indication of a honograph or graphophone with a recor 11 in place thereon and the stylus 12 shownin contact with the upper face of the record.

13 is the horn through which the sound from the diaphragm is emitted. v The modifier device is shown in lace in the throatof the horn in Fig. 1. T e main'bddy of said device is a piriform metallic shell 14, having its lesser end open and its greater end provided with a restricted two-1i ped orifice 15. Said piriform' shell is provide with a pair of rubber washers or muflilers lfi, 16 for retainingthe device in lace in the throat of the horn and preventing sound vibrations from passing around thea'foresaid shell exteriorly. A resonant metallic reflector 17 is secured within the greater end of the piriform shell v14. This reflector has a diameter slightly less than the greatest inner diameter of the shell and about the same curvature as the portion of the shell adjacent to it, and is so supported bythe lugs 18 18 that it is nowhere in contact with the inner surface of said shell, thus making a narrow passage entirely around said reflector between it and the'inner face of the shell and leading to the orifice 1o, which is opposite the convex top of said reflector.

I A handle 19 is provided to facilitate placing the device in the throat of the horn removing it therefrom.

The sound-wavesgiven out from the dia-.

through the basal portion of the throat of the horn enter the open lesser end ofthe piriform shell and impinge against the inner surface of the reflector. some portion. of these vibrations may pass through said reflector directly into the open space between its outer surface and the inner face of the shell, and thus be transmitted to and through the orifice 15 but a great partis entirely absorbed and the remainder reflected against the inner face of the middle portion of the shell and thence further transmitted, by

repeated reflections, throu h the narrow space around the reflector, etween it and t e inner face of the shell, to and through the orifice 15. The net result ofthis absorption and repeated reflection of the sound vibrations is found to be'a substantial reduc- 7 5 tion of the volume of the sound and the removal of all or nearly all of the metallic timbre that is a commonly unpleasant fea ture of the rendering of any record upon a phonograph. -8o

The form given the shell and reflector may be varied to some extent; but its general character must be such that few of the soundwaves coming from the basal portion of the throat of the incidence of the waves, and the rubber 9o mufliers provided on the exterior of the piriform shell prevent any sound vibrations from passing around it, with the result that .all not absorbed by said mufliers must pass through the shell and be subjected to the 5 interference of its inner walls and contained reflector. It is found that the orifice in the outer or greater end of the shell should be relatively small and that the softest and least metallic or whistling effect is secured by we having such orifice somewhat elongated and outwardly lipped.

My invention is shown in the drawings as embodied in a particular and preferable form; but it may be otherwise embodied 105 within the scope of the claims hereinafter made and as distinguished from prior devices for like purpose.

I claim- 1. A modifier for phonographs, adapted to I [0 phragm of the phonograph and transmitted horn shall be permitted to pass without impinging upon said reflector and its lesser end open and its greater endpro vided with a restricted orifiee,-.a resonant. reflector secured within said greater end of the shell, and a muffler whereby --sound'-v-ibrations are prevented from passing around %ai((i1.shell-.exterior1y, substantially as speci- 2. A modifier for phonographs, adapted to l fit in the throat of the horn, and consisting :in the combination of, apii'iform metallic "ing its lesserend' open audits greater end prov1 edwith a're strictedlippe'd orifice, a resonant reflector securedwithin said ater end of -the shell, and :a :muiiler wfieby soundwibrations are-preventedlfrompassing around said shell exteriorly, substantially as specified.

'4. .A-moldifier'for phonographs, adaptedto 'fit inthe'throat ofthe hornyand consisting inithe'combination df,a-piriform shell having itslesser-end'open-and its greater end provided-With a'restricted orifice, a' resonant reflector secured within .said I greater 1 end of the shelland convezdy'presentcdto said orifice, and. amu'fflerwhereby sound-vibrations are prevented from passing "around said shell-exteriorly, substantially as specified.

5. A modifier for'phonographs, adaptecrto fitin'the throat of the horn, and consisting in'the combination of, a;piriform shell having its lesser end open and its greater end 'provided withmirestricted orifice, a resonant reflector secured within said greater end of the .shell ...and nearly equaling .the 'greatest inner diameter thereof, and a muffler whereby sound-Vibrations are prevented from passing around said shell exteriorly, substan-' tially as specified.

"6. A modifier 'forphonographs adapted to fitinithe throatof the horn, and consisting .ir'r'the combination of, a piriform'shell E having itslesser'endopen andits greater'end providedwitha"restricted-"oflficeparesonant reflector secured within said "greater end -'of the shell, and mufiiers whereby soundvibra tions areprevented from passingaround said shell'exteriorly, sdbstantially'as specified.

" 7. 'A'modifier forphonographs; adaptedto fit within the throat of the horn; and consisting in the combination of; a' piriformmetallic shell having its lesser rend open and 'its greater end provided-with airestricted li ped orifice, a resonant "reflector -securedw thin said greater end of 'the rs'helhand 'nearly equaling 1 the greatest inner diameter'therecf and conveXly-presented -to said 'o rifice, and

"Inufiiers "whereby sound yib'rations are prevented from passing around said "shelteriteriorly, substantially-as-specified.

In testimony whereof lhave hereunto set my hand in the presence of two subscribing nSHIiE-Y -S."THOMPSN.

witnesses.

Witnesses HENRY Lovn 'Cmnnn I. F. STEVENS. 

